Re: [dpdk-dev] [PATCH v2 2/5] devargs: refactor scratch buffer storage

[Thomas Monjalon <thomas@monjalon.net>]

18/01/2021 16:16, Xueming Li:
> In current design, legacy parser rte_devargs_parse() saved scratch
> buffer to devargs.args while new parser rte_devargs_layers_parse() saved
> to devargs.data. Code using devargs had to know the difference and
> cleaned up memory accordingly - error prone.
> 
> This patch unifies data the dedicate scratch buffer, introduces
> rte_devargs_free() function to wrap the memory memory clean up.
> 
> Signed-off-by: Xueming Li <xuemingl@nvidia.com>
> ---
> --- a/lib/librte_eal/include/rte_devargs.h
> +++ b/lib/librte_eal/include/rte_devargs.h
> @@ -60,16 +60,16 @@ struct rte_devargs {
>  	/** Name of the device. */
>  	char name[RTE_DEV_NAME_MAX_LEN];
>  	RTE_STD_C11
> -	union {
> -	/** Arguments string as given by user or "" for no argument. */
> -		char *args;
> +	union { /**< driver-related part of device string. */
> +		const char *args; /**< legacy name. */
>  		const char *drv_str;
>  	};
>  	struct rte_bus *bus; /**< bus handle. */
>  	struct rte_class *cls; /**< class handle. */
>  	const char *bus_str; /**< bus-related part of device string. */
>  	const char *cls_str; /**< class-related part of device string. */
> -	const char *data; /**< Device string storage. */
> +	char *data; /**< Scratch buffer. */
> +	const char *src; /**< Arguments given by user. */

Adding a field changes the size of the struct, which is an ABI break.
We need to plan this change for DPDK 21.11.
Let's think what can be done in the meantime.